Fuel burning apparatus



.Nov. 7, 1939. c. w. ROBBINS FUEL BURNING APPARATUS Filed June 20, 1936 INVENTOR. CHARLES W fiaaa/A/s mam ATTORNEYS.

' Patented Nov. 7, 1939 UNITED STATES PATENT OFFICE FUEL BURNING APPARATUS Application June 20, 1936, Serial No. 86,370

Claims.

This invention relates to gas burning apparatus and has particular reference to a conversion burner in the form of a unit which is adapted to be inserted through the door or lateral open- 5 ing leading into the ash pit of a furnace or boiler initially designed for burning solid fuel.

The 'principal object of the present invention is to increase the amount of primary air which is supplied to the burner or burners and therefore to increase the efliciency and rating of the latter.

The above object is attained by the provision of features of construction and arrangement within the casing of the unit for controlling the flow of air passing lengthwise through the easing to supply the primary and secondary air needed for combustion, the arrangement being such as to so control the flow of air that a larger percentage is entrained with the gas passing to the main burner or burners than has heretofore been possible.

Th invention may be briefly summarized as consisting in certain novel combinations and arrangements of parts which Will be described in the specification and set forth in the appended claims.

In the accompanying sheet of drawings,

Fig, 1 is a vertical sectional view of a conversion unit constructed in accordance with my invention; and

Fig. 2 is a transverse sectional view substantially along the line 2--2 of Fig. l.

Referring now to the drawing, the unit includes a casing H) which is generally rectangular in shape, as indicated in Fig. 2, and is -adapt-' ed to extend laterally and horizontally through the ash pit door where it will be supported and sealed in any desired manner. The structure of the furnace is indicated conventionally at II. However, no attempt is being made to show the actual construction of the furnace wall orthe method of sealing the unit in the opening thereof. The unit will be supported in operative position in any suitable manner, the front being shown in this instance supported by legs l2 while a suitable support will be placed under the inner end of the unit beneath the burner or burners.

The major portion of the unit extends inwardly beyond the wall I I with a part projecting outwardly, and this part will have suitable provision for the admission of air which flows through the casing and is divided into primary and secondary air required for proper combustion. In this instance, the air is admitted to the casing [0 through a series of openings or slots in the form of louvre openings l3 arranged at the front end of the unit which, since it is exposed, may beconstructed and ornamented in any desired manner.

At I4 is shown the, burner or burners, a burner of the ring type being herein illustrated which may be in either one or two sections, but in this instance a two-section burner is illustrated. A mixture ofgas and air is supplied to the burner by mixing tubes l5 one being shown in Fig. 1 10 and portions of both in Fig. 2. The main gas supply pipe is not shown but it leads to a suitable valve located at the outer part of the casing and here shown as a diaphragm valve I from which extends a delivery pipe I! communi- 15 eating with a manifold l8 shown in section in Fig. 1. Whether the pipe I! leads to a manifold and-thence to a plurality of mixing tubes or to a single mixing tube I5, is, however, immaterial,

As usual, the gas is delivered from the manifold to each mixing tube by a nozzle I9 so that the gas stream or jet will entrain the primary air therewith. As is customary, the orifice of the nozzle is controlled by a valve to vary the size of the gas jet and the velocity of the'gas passing from the nozzle. In this instance the valve is adjusted by arod 20 which is adapted to be turned and which extends forwardly beyond the furnace wall to a point for convenient adjustment, it being noted that the mixing of gas from 'the primary air and the admission of primary air to the mixing tubes l5 occur near the inner end of the casing"!!! a distance inwardly from the front wall of the furnace.

Provision is made for shutting off or stopping 35 the fiow of air through the casing when the main 'valve I6 is closed and permitting the air to flow through the casing when the valve I6 is opened. This is accomplished by means of a door 22 hinged at its lower edge and extending crosswise of the casing so as to open and close an opening 23 which is located in the casing at or about the point where the latter extends through the furnace wall 1 I, this opening 23 and the air valve or door 22 being located above a fixed partition 24 which extends across the lower part of the casing just inwardly of the valve Hi. When a gas valve of the diaphragm type is employed, the door is operated concurrently with the operation of the valve by a plunger or pressure responsive device 25 which may be connected to a diaphragm in a casing 26. The chamber above the diaphragm of the valve It may be connected by a pipe 21 to the chamber beneath the diaphragm in the casing 26 so that, when pressure 55 is supplied above the diaphragm of the gas valve it, it will also be supplied beneath the diaphragm within the casing 26 so as to close the door, and when pressure is relieved above the diaphragm 5 of the valve I6, it will be relieved beneath'the 0 lever 23 has a counterweight 30 which substantially balances the weight of the door 22. As these parts per se do not form a part of the present invention, further reference to them is unnecessary.

There also extends through the casing l0 a small tubular casing 3| which at its inner end has an upright extension 31a. The pipe for the pilot gas extends through the horizontal part of the casing 3i and supplies gas to the pilot 32 which is in igniting relation to the main burner I4 and stands just in front of the upright portion 3 la of the casing 3i. Projecting out through the. top of the upright portion 3la of the casing 3i is a thermal element 33 which extends down through the portion 3; of the casing 3i and has a control member extending through the casing 3i to a switch box indicated at 34 and containing switch elements utilized in connection with the control circuit for the valve i6 including the coil of a solenoid control valve. These parts likewise form no part of the present invention and further description is deemed unnecessary.

Coming now to the features constituting the -main part of the invention, it will be observed that I provide immediately in front of the mixing tubes IS a baflle 35 whlchextends across the lower part of the casing i0. Likewise, it will be observed that the mixers 39, which are located at the rear ends of the mixing tubes i5 and into 0 which the gas nozzles i9 extend, are provided of the mixers immediately above the baille 35 and are in inclined position, the arrangement of the bafiie and these openings being such that the air which passes inwardly through the casing l0 (primary air andsecondary air) is required to pass over the baffle 35 and a part of it to sweep over the primary air openings 31.

It will be observed also that associated with each primary air opening 31 is a shutter 33 which is hinged at 39 and biased toward open position by a spring 40. The hinge 39 for the shutter is supported on the mixer of each burner tube at the rear of the primary air opening 31 and the shutter extends forwardly and normally upwardly over the opening 31 in a manner such that the shutter 33 acts as a scoop or diverter to enhance the flow of primary air through the openings 31 and into the mixers.

The position of each shutter may be adjusted by turning a rod H which extends horizontally from a point adjacent the baflle 35 forwardly to the front part of the casing I0 outside the furnace wall where it can be conveniently reached and turned when adjustment is desired. In this instance the forward end of the rod 4| engages a pin 42 which is mounted for endwise movement in the upperpart of the mixer and at its forward 0 end engages a downturned flange 43 of the shutter at the rear of the hinge pin 39. The rod ll has a threaded connection with the manifold l3 so that when the rod ll is turned in one direction it moves the pin 42 forwardly so as to move the and when the rod 4! is turned in the reverse direction, the action of the spring 40 is to open the shutter.

With this arrangement, the air which passes through the casing l0, i. e., both primary and secondary air, is all required to pass over the baille 35 and part of the air sweeps over the inclined primary air inlet openings 31 which are so arranged that the air tends to sweep into these openings to augment the flow created by the suction efiect of the gas jets. Furthermore, this action is augmented by the deflecting or scooping eifect of the shutters 31. Thus by the velocity eifect and by the deflector action of the shutters the primary air which enters the burner tubes is augmented, permitting an increase in the gas rate to a higher figure than would otherwise be possible without detriment to the flame characteristics. thus increasing the rating of the burner. Of course, the amount, of primary air can be varied whenever desired by adjusting the shutters 38.

While I have shown one embodiment of the invention which operates very effectively, I do not desire to be confined to the details of arrangement or construction which have been illustrated but aim in my claims to cover all modifications which do not involve a departure from the spirit and scope of the invention in its broadest aspects.

Having thus described my invention, I claim:

1. In gas burning apparatus, a main burner, a duct adapted to extend through a lateral door of the furnace or the like and adapted to convey primary and secondary air to the burner, the burner having a mixing tube with an air inlet opening located in the casing, a baflle extending across the lower part of the casing so that the primary and secondary air is required to pass over the same, and a shutter above the baflie over the opening for the mixer.

2. In gas burning equipment, a burner, a duct for conveying primary and secondary air adapted to extend inwardly through a lateral opening in the wall of the furnace or the like and to project into the ash pit of the latter, a mixing tube connected with the burner and having a mixing end with an air inlet opening controlled by an adjustable shutter, and a baille extending across the duct for diverting primary and secondary air and causing it to flow over the same and part of it toward the opening and its shutter.

3. In gas burning equipment, a burner, a conduit adapted to extend substantially horizontally into a furnace and having at or near its forward end an air inlet opening and at or near its inner end an outlet opening for the flow of secondary air to the burner, a burner tube connected to the burner and extending forwardly into the conduit and provided with a mixing chamber having a primary air opening, and a deflector adjacent said opening and in inclined relation with respect to the direction of air flow through the conduit whereby the amount of primary air supplied to the burner tube is augmented by the deflecting or scooping eifect of the deflector.

4. In gas burning equipment, a burner, a conduit adapted to extend substantially horizontally into a furnace and having at or near its forward end an air inlet opening and at or near its inner end an outlet opening for the flow of secondary air to the burner, a burner tube connected to the burner and extending forwardly into the conduit and provided with a mixing chamber having a primary air opening which is inclined upwardly and rearwardly with respect to the direction of air flow through the conduit whereby the amount of primary air admitted to the burner tube is augmented by the velocity effect of the air passing through the conduit, and a baifle extending crosswise of the conduit in front of said primary air opening.

5. In gas burning equipment, a burner, a conduit adapted to extend substantially horizontally into a furnace and having at or near its forward end an air inlet opening and at or near its inner end an outlet opening for the flow of secondary air to the burner, a burner tube connected to the burner and extending forwardly into the conduit and provided with a mixingchamber having a primary air opening, a' deflector adjacent said opening and in inclined relation with respect to the direction of air flow through the conduit whereby the amount of primary air supplied to the burner tube is augmented by the deflecting or scooping effect of the deflector, and a bafile extending across the conduit in front of said dem 

